Fluoxetine in Pulmonary Arterial Hypertension (PAH) Trial

Change in PVR between baseline and follow-up will be utilized. PVR is calculated as [(Pulmonary Artery mean - wedge) / Fick Cardiac Output]. Fick CO will be used in computing PVR over thermodilution because Fick appears to have greater precision (but not accuracy). The calculation of PVR above is measured in woods unit. Change is derived by getting the difference between baseline and week 24 PVR (Week 24 minus Baseline). mean is then computed by getting the average of the change

Urine for spot urine 5-HIAA will be collected at baseline and Week 24. Subjects will be on diet restriction 72 hours prior to urine collection. Sample will be the first morning urine on the visit day. Sample will be brought to site and then sent to affiliate outside laboratory for processing. 5HIAA results are expressed as a ratio to creatinine excretion in the unit "mg/g creatinine" Change 5-HIAA is derived by getting the difference between baseline and week 24 5HIAA results (Week 24 minus Baseline). mean is then computed by getting the average of the change

About 20ml blood will be obtained for plasma and serum at Baseline and Week 24. This will be placed in a red-top tube (serum, at least 1 ml) and blue-top tube. For the plasma tests, a plasma volume of 750 microL is required. Samples will be sent together, as a batch of 50 is required, on dry ice via overnight courier. Plasma will be obtained by drawing blood into a blue-top citrated tube, inverting the tube 6 times, and then centrifuging at 2000g for 10 minutes. The platelet poor plasma will be drawn off, and then re-centrifuged for 10 minutes before freezing.

Exercise capacity will be measure using the 6-minute walk test. Data collected at baseline and 24 were analyzed. The test will follow the ATS guidelines for 6MWT at all time.

Functional class will be measured using the WHO functional class assessment. This is graded from WHO FC I to FC IV. Assessment will be completed by an investigator on the study at every visit.

Patient reported outcome will be assessed using the Quick Inventory of Depressive Symptomatology (16-Item) (Self-Report) (QIDS-SR16) completed at baseline, week 12 and Week 24; baseline and week 24 reported. Each question is scored from minimum of 0 to a maximum of 3; total score ranges from 0 to 42. With zero being better outcome and 42 being severe outcome

PGIS questionnaire will be administered for global assessment of severity. This questionnaire is categorical and measures outcome from "none" being best outcome to "severe" being the worst outcome

Global assessment of severity will be determined using Clinician global impression of severity - symptoms (CGIS). This questionnaire is categorical and measures outcome from "none" being best outcome to "severe" being the worst outcome

Patient reported outcome will also be assessed using SF-36 completed at baseline, Week 12 and Week 24. The SF-36 consists of eight scaled scores, which are the weighted sums of the questions in their section. Each scale is directly transformed into a 0-100 scale on the assumption that each question carries equal weight. The lower the score the more disability. The higher the score the less disability i.e., a score of zero is equivalent to maximum disability and a score of 100 is equivalent to no disability. The eight sections are: vitality, physical functioning, bodily pain, general health perceptions, physical role functioning, emotional role functioning, social role functioning, and mental health

CGI-change questionnaire will be completed for global assessment of severity. This questionnaire is categorical and measures outcome from "very much better" being best outcome to "very much worse" being the worst outcome